The US treasury isn't the only issuer of bonds. Corporations also issue bonds that have future payment structures like U. Treasuries.

The US treasury isn't the only issuer of bonds. Corporations also issue bonds that have future payment structures like U.S. Treasuries. Of course, unlike the federal government, corporations can go bankrupt, leaving their bondholders unable to collect all of their scheduled payments. Because of this risk of default, corporate bonds must have a higher yield in equilibrium than similarly structured Treasury bonds. Under what conditions, if any, might you expect to see corporate bond yields rise while Treasury Bond yields fell ?